Worked example: interest in Texas

Example inputs

Run this scenario in DocketMath using the Interest calculator.

Below is a worked example of an interest calculation in Texas using DocketMath’s Interest calculator (/tools/interest). This example uses the general/default Texas period described in Texas Code of Criminal Procedure, Chapter 12:

• General SOL period: 0.0833333333 years

  • That equals 1 month (because 0.0833333333 × 12 ≈ 1).
• Source: Texas Code of Criminal Procedure, Chapter 12 (see https://statutes.capitol.texas.gov/Docs/CR/htm/CR.12.htm)

To make the example concrete, assume the following scenario:

Scenario (dates)

• Start date (accrual start): January 1, 2025
• End date (accrual end / lookback end): February 1, 2025

That gives a time window of exactly 1 month, consistent with the general SOL period of 0.0833333333 years.

Scenario (financial inputs)

For the interest math, the calculator typically needs:

• Principal (P): $5,000
• Annual interest rate (r): 12% per year
• Interest model (simple vs. compounded): for this worked example, we’ll use simple interest over the selected window (and you should match the calculator setting to get the same numeric result).

Conversion used by the example

Because the jurisdiction data expresses the period in years as 0.0833333333, the example uses:

• Time fraction (t): 0.0833333333 years

Example run

Here’s the interest computation step-by-step, using the general/default Texas period (1 month).

Run the Interest calculator using the example inputs above. Review the breakdown for intermediate steps (segments, adjustments, or rate changes) so you can see how each input moves the output. Save the result for reference and compare it to your actual scenario.

Step 1: Identify the time fraction

• SOL-based window: 0.0833333333 years

So:

• t = 0.0833333333

Step 2: Use the simple interest formula

Simple interest is typically computed as:

• Interest (I) = P × r × t

Plug in:

• P = 5,000
• r = 0.12
• t = 0.0833333333

Compute:

• 0.12 × 0.0833333333 = 0.009999999996 ≈ 0.01
• I = 5,000 × 0.01 = 50

Step 3: Compute total amount due (if the calculator shows it)

• Total = P + I = 5,000 + 50 = $5,050

What DocketMath’s output would look like

When you run this in DocketMath’s Interest calculator (/tools/interest), the results typically include the time period used and the computed interest (and often the principal + interest total).

A clear representation of the result:

Quick check: If your DocketMath run is set to compounded interest rather than simple interest, the interest amount for a short 1-month window can differ slightly. Verify the calculator’s interest model setting to match the method used in this example.

Sensitivity check

Interest changes in a predictable way when you adjust inputs. This section shows how the outcome shifts when you change rate or time, holding principal constant ($5,000).

To test sensitivity, change one high-impact input (like the rate, start date, or cap) and rerun the calculation. Compare the outputs side by side so you can see how small input shifts affect the result.

Sensitivity A — change the rate, keep time fixed at 1 month

Keep:

• t = 0.0833333333
• P = $5,000

Use I = P × r × t (simple interest).

Takeaway: With simple interest, the 1-month interest is linear in the annual rate—double the rate, and the interest doubles.

Sensitivity B — change the time window, keep rate fixed at 12%

Keep:

• r = 12%
• P = $5,000

If the tool allows custom windows or derives the year fraction from date differences, then the year fraction changes. Using illustrative time fractions:

1. 0.5 months → t = 0.04166666665 years
2. 1.0 month → t = 0.0833333333 years (the example above)
3. 2.0 months → t = 0.1666666666 years

Compute:

• I = 5,000 × 0.12 × t

Takeaway: For simple interest, interest is linear in time—double the time window, and the interest doubles.

Sensitivity C — confirm the general/default period is the one being used

Because the jurisdiction data provided:

• General SOL period: 0.0833333333 years
• No claim-type-specific sub-rule was found

…it’s important to ensure the calculator is actually applying the general/default time rule you intended.

Before relying on results from /tools/interest, check:

• Does the calculator display the time fraction used (for example, 0.0833333333 years)?
• Do the selected dates match the intended ~1 month window?
• Is the calculator using simple vs. compounded interest?
• Does the principal entered into the calculator match the document amount (entered once, not duplicated)?

Practical note: If different date selections produce slightly different day counts, some systems convert dates to a year fraction using a particular convention. That can cause small differences even when you expect the window to be “about one month.” The best way to confirm is to read the time fraction shown by the calculator.

Gentle disclaimer: This example is for demonstration of the mechanics of an interest calculation and how a tool might implement a time fraction. It isn’t legal advice.

Related reading

• Interest rule lens: Maine — The rule in plain language and why it matters
• Common interest mistakes in Rhode Island — Common errors and how to avoid them
• Worked example: interest in Maine — Worked example with real statute citations